MBM29F033C Fujitsu Media Devices, MBM29F033C Datasheet - Page 15

• Manufacturer Part Number: MBM29F033C
• Description: 32M (4M X 8) BIT
• Manufacturer: Fujitsu Media Devices

Temporary Sector Group Unprotection
Notes: 1. Address bits A
* : Either of the two reset commands will reset the device.
Command Definitions
Read/Reset*
Reset/Read*
Autoselect
Byte Program
Chip Erase
Sector Erase
Sector Erase
Suspend
Sector Erase
Resume
This feature allows temporary unprotection of previously protected sector groups of the MBM29F033C device
in order to change data. The Sector Group Unprotection mode is activated by setting the RESET pin to high
voltage (12 V). During this mode, formerly protected sector groups can be programmed or erased by selecting
the sector group addresses. Once the 12 V is taken away from the RESET pin, all the previously protected sector
groups will be protected again. Refer to Figures 13 and 20.
Device operations are selected by writing specific address and data sequences into the command register.
Writing incorrect address and data values or writing them in the improper sequence will reset the device to the
read mode. Table 6 defines the valid register command sequences. Note that the Erase Suspend (B0H) and
Erase Resume (30H) commands are valid only while the Sector Erase operation is in progress. Moreover, both
Read/Reset commands are functionally equivalent, resetting the device to the read mode.
Command
Sequence
2. Bus operations are defined in Table 2.
3. RA = Address of the memory location to be read.
4. RD = Data read from location RA during read operation.
5. Read and Byte program functions to non-erasing sectors are allowed in the Erase Suspend mode.
6. X = “H” or “L”
Sector Address (SA).
PA = Address of the memory location to be programmed. Addresses are latched on the falling edge
SA = Address of the sector to be erased. The combination of A
PD = Data to be programmed at location PA. Data is latched on the rising edge of WE.
of the WE pulse.
select any sector.
Req'd
Cycle
Write
Bus
1
3
3
4
6
6
1
1
s
18
Erase can be suspended during sector erase with Addr (“H” or “L”). Data (B0H)
Erase can be resumed after suspend with Addr (“H” or “L”). Data (30H)
XXXH F0H
XXXH AAH XXXH 55H XXXH F0H
XXXH AAH XXXH 55H XXXH 90H
XXXH AAH XXXH 55H XXXH A0H
XXXH AAH XXXH 55H XXXH 80H XXXH AAH XXXH 55H XXXH 10H
XXXH AAH XXXH 55H XXXH 80H XXXH AAH XXXH 55H
Write Cycle
Addr. Data Addr. Data Addr. Data Addr. Data Addr. Data Addr. Data
to A
First Bus
21
Table 6
= X = “H” or “L” for all address commands except or Program Address (PA) and
Second Bus
Write Cycle
MBM29F033C Command Definitions
—
—
Write Cycle
Third Bus
—
—
MBM29F033C
Fourth Bus
Read/Write
RA
PA
—
—
21
Cycle
, A
20
, A
RD
PD
—
—
19
, A
Write Cycle
18
Fifth Bus
—
—
—
—
, A
17
, and A
—
—
—
—
-70/-90/-12
16
Write Cycle
will uniquely
Sixth Bus
SA
—
—
—
—
30H
—
—
—
—
15